Ext.regModel("Album", {
    idProperty: "id",
    fields: [
        {name: "id"},
        {name: "name"},
        {name: "owner"},
        {name: "cover"}
    ],
    proxy: {
        type: 'scripttag',
			 callbackParam: 'callback',
			 callback: function(){
			 console.log('plop');  
			 },
        reader: {
            root: 'albums',
            type: 'json'
        }
    },
    callback: function(){
        console.log("load album");
    }
});